The Vienna Ab initio Simulation Package (VASP) is a computer program for atomic scale materials modelling, e.g. electronic structure calculations and quantummechanical molecular dynamics, from first principles.
VASP computes an approximate solution to the manybody Schrödinger equation, either within density functional theory (DFT), solving the KohnSham equations, or within the HartreeFock (HF) approximation, solving the Roothaan equations. Hybrid functionals that mix the HartreeFock approach with density functional theory are implemented as well. Furthermore, Green's functions methods (GW quasiparticles, and ACFDTRPA) and manybody perturbation theory (2ndorder MøllerPlesset) are available in VASP.
In VASP, central quantities, like the oneelectron orbitals, the electronic charge density, and the local potential are expressed in plane wave basis sets. The interactions between the electrons and ions are described using normconserving or ultrasoft pseudopotentials, or the projectoraugmentedwave method.
To determine the electronic groundstate, VASP makes use of efficient iterative matrix diagonalisation techniques, like the residual minimisation method with direct inversion of the iterative subspace (RMMDIIS) or blocked Davidson algorithms. These are coupled to highly efficient Broyden and Pulay density mixing schemes to speed up the selfconsistency cycle.
The following is a (by no means complete) list of VASP features:
Functionals

First derivatives


Dynamics and relaxation

Magnetism


Linear response to electric fields

Linear response to ionic displacements


Optical properties

Berry phases


Green's function methods

Manybody perturbation theory
